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# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 991def index_name_for_remove(table_name,options={})index_name=index_name(table_name,options)unlessindex_name_exists?(table_name,index_name,true)ifoptions.is_a?(Hash)&&options.has_key?(:name)options_without_column=options.dupoptions_without_column.delete:columnindex_name_without_column=index_name(table_name,options_without_column)returnindex_name_without_columnifindex_name_exists?(table_name,index_name_without_column,false)endraiseArgumentError,"Index name '#{index_name}' on table '#{table_name}' does not exist"endindex_nameend